Effect of Partial Replacement of Forage Neutral Detergent Fiber with By-Product Neutral Detergent Fiber in Close-Up Diets on Periparturient Performanc

TOP ABSTRACT INTRODUCTION MATERIALS AND METHODS RESULTS AND DISCUSSION CONCLUSIONS ACKNOWLEDGEMENTS REFERENCES

Abstract
The objective of this study was to determine the effect of partial replacement of forage neutral detergent fiber (NDF) with by-product NDF in close-up diets of dairy cattle on periparturient metabolism and performance. Holstein cows (n = 45) and heifers (n = 19) were fed corn silage-based diets containing 1) 30% oat hay, or 2) 15% oat hay and 15% beet pulp from d –21 relative to expected parturition until parturition. After parturition, all animals received the same lactation diet. Animals were group-fed from d –21 to –10 relative to expected parturition and fed individually from d –10 until 14 d in milk. Animals were required to have at least 5 d of prepartum dry matter intake (DMI) data to remain on the study. Data were analyzed as a randomized design and subjected to ANOVA using the MIXED procedure of SAS. Close-up diet did not affect DMI, total tract nutrient digestibility, energy balance, or serum content of nonesterified fatty acids and ß-hydroxybutyrate during the last 5 d prepartum. Prepartum body weight and body condition score were similar between treatments. There was no carryover effect of close-up diet on DMI, energy balance, milk yield, body weight, body condition score, or serum content of nonesterified fatty acids and ß-hydroxybutyrate during the first 14 d in milk. In summary, partial replacement of forage NDF (oat hay) with by-product NDF (beet pulp) did not affect periparturient metabolism or performance.

Key Words: intake • neutral detergent fiber • nonforage fiber source • transition cow

5 MATERIALS: APPARATUS, REAGENTS, SAMPLES

5.1 Introduction

Quality analytical work can only be performed if all materials used are suitable for the job, properly organized and well cared for. This means that the tools are adequate and in good condition, and that sample material receives attention with respect to proper handling, storing and disposal.

The tools used for analysis may be subdivided into four categories:

1 Primary measuring equipment (pipettes, diluters, burettes, balances, thermometers, flow meters, etc.)

2. Analytical apparatus or instruments.

3. Miscellaneous equipment and materials (ovens, furnaces, fridges, stills, glassware, etc.)

4. Reagents.

The saying that a chain is as strong as its weakest link applies particularly to these items. An analyst may have gone out of his/her way (as he/she should) to prepare extracts, if the cuvette of the spectrophotometer is dirty, or if the wavelength dial does not indicate the correct wavelength, the measurements are in jeopardy. Both the blank and the control sample (and a possible "blind" sample or spike) most likely will reveal that something is wrong, but the harm is already done: the problem has to be found and resolved, and the batch might have to be repeated. This is a costly affair and has to be minimized (it is an illusion to think that it can be totally prevented) by proper handling and maintenance of the equipment.

Also the quality and condition of a number of other working materials have to be watched closely. The calibration of thermometers, burettes and pipettes, particularly the adjustable types, may exceed the acceptable tolerance (and be put out of use). New glassware may look clean but always needs to be washed. Glassware may give off unwanted elements (boron, silicon, sodium). The same goes for milling and grinding equipment (pestles and mortars, tungsten carbide grinders, brass or steel sieves). For virtually all analyses glassware needs to be rinsed with deionized water after washing. Therefore, if glassware, such as volumetric flasks, is shared by analysts, they should be able to rely on the loyalty and good laboratory practice of their colleagues.

A similar reasoning applies to reagents. One of the most prominent sources of the errors made in a laboratory is the use of wrongly prepared or old reagents. Therefore, reagents have to be prepared very carefully and exactly following the prescriptions, they have to be well labelled and expiry dates have to be observed closely. Filtering a pH buffer solution in which fungi are flourishing may save time and reagent but is penny-wise and pound-foolish.

Of equal importance for the quality of the work is the proper handling of the sample material. Not only the technical aspects such as sample preparation, but particularly the safeguarding of identity and integrity of the samples as well as the final storage or disposal (chain of custody).

As part of the overall quality assurance, in this chapter a number of instructions and suggestions are presented to ensure the analytical reliability of the main tools and proper organization of sample handling.

Articles

Physico-Chemical Properties, Composition and Oxidative Stability of Camelina sativa Oil Oxidative Stability of Camelina sativa Oil

Summary
Camelina sativa is a cruciferous oilseed plant. With the aim of describing the general characteristics of the oil obtained from the seeds of plants grown in Slovenia and of comparing it to camelina oil from other countries we determined some physico-chemical properties, fatty acid composition, iodine and saponification value and followed its oxidative stability under different storage conditions. The density at 20 °C was (0.9207 ± 0.0001) g/cm3 and the refractive index reached 1.4756 ± 0.0001 at 25 °C. The analysis of fatty acids showed 10.3 % of saturated and 55.8 % of polyunsaturated acids, with 16.9 % of linoleic(C18:2), 35.2 % of a-linolenic (C18:3w3) and 1.6 % of erucic acid (C22:1). Determination of oxidative stability of this highly unsaturated oil revealed that the formation of primary oxidation products was affected by photooxidation. The peroxide value, PV, of fresh oil was (2.38 ± 0.01) meq O2/kg, while after 1 month in daylight at room temperature PV reached (21.0 ± 0.1) meq O2/kg. When stored in darkness PV was (8.12 ± 0.08) meq O2/kg. In the fresh oil, the p-anisidine value, AV, was 6.2 ± 0.1, after 11 months at room temperature 10.4 ± 0.1, and after the same time at 8 °C in darkness 7.1 ± 0.1. Susceptibility to oxidation of camelina oil was measured by the Rancimat test and expressed as the induction period. In fresh camelina oil the induction period was 4.8 h.
Key words: Camelina sativa oil, fatty acids, omega-3 fatty acids, density, refractive index, ox-
idative stability

[PDF] Physico-Chemical Properties, Composition and Oxidative Stability ...

Oil and Fatty Acid Diversity in Genetically Variable Clones of Moringa oleifera from India

Abstract: The physico-chemical properties of oil from Moringa oleifera seeds from India were determined in the present study. The petroleum ether extracted oil ranged from 27.83 - 45.07% on kernel basis and 15.1-28.4% on whole seed basis in 20 different clones. Leaves and pods showed a good source of vitamin C. Oleic acid (C18:1) has been found to be the major fatty acid being 78.91-85.52% as compared to olive oil, which is considered to be richest source of oleic acid. All the clones from India did not show any presence of behenic acid (C 22:0). The oil was also found to contain high levels of β-sitosterol ranged from 42.29-47.94% stigmasterol from 13.66-16.61%, campesterol from 12.53-16.63%. The γ- and δ-tocopherol were found to be in the range of 128.0-146.95, 51.88-63.5 and 55.23-63.84 mg/kg, respectively.

Key words: Moringa oleifera, seed oil, oleic acid, genetic variability

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Determination of the total base number (TBN)in petrochemical products by potentiometric HClO4 titration

Summary
The base numbers of three different lubricating oil samples were determined. Work was carried out using different electrode systems in different solvent mixtures (glacial acetic acid/toluene and glacial acetic acid/chlorobenzene) and with different titration modes (drift and time-controlled dynamic titrations). The results obtained displayed no significant differences in their reproducibility and were all within the tolerance limits.


Articles

Titration in use of fatty acid methyl esters

A Metrohm UK product story

Edited by the Manufacturingtalk editorial team Apr 27, 2006

The manufacture and use of Fatty Acid Methyl Esters (FAME), has implications for the environment.

The manufacture and use of Fatty Acid Methyl Esters (FAME), has implications for the environment. Bio diesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Bio diesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a bio diesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Bio diesel is simple to use, biodegradable, non-toxic, and essentially free of sulphur and aromatics. Bio diesel is made through a chemical process called transesterification whereby the glycerine is separated from the fat or vegetable oil. The process leaves behind two products -- methyl esters (the chemical name for bio diesel) and glycerine (a valuable by-product usually sold to be used in soaps and other products). Fuel-grade bio diesel must be produced to strict industry specifications (ASTM D6751) in order to insure proper performance. Bio diesel is the only alternative fuel to have fully completed the health effects testing requirements of the 1990 Clean Air Act Amendments.

Articles

Salt shake-up.(PLANT & EQUIPMENT)

Publication: Food Trade Review

Publication Date: 01-SEP-05

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Full-Text Online Journals Research online. Academic journals & books at Questia Online Library. Water Quality Meters Testers and meters for Laboratories for all your needs Water in Solvents From PPM to % analysis of water in organic solvents with a solid state Labcaire Systems Ltd Wide range of fume cupboards to suit most laboratory requirements COPYRIGHT 2005 Food Trade Press Ltd. With children's food salt content being closely monitored, Metrohm UK have developed a favourably priced and easy to use analytical solution for sodium analysis. In May 2003, the Food Standards Agency (FSA) announced guidelines on maximum recommended salt intakes for children. At the time, the Food Commission warned that with so much hidden salt in children's food, it would be hard for parents to achieve the targets without a significant reduction of salt in processed food. The Food and Drink Federation (FDF, representing the food industry) announced that it would work with its industry members to reduce salt content in soups and sauces by 10%. There have been mixed results in the successes of this over the last two years but one point is very clear; parents are more aware than ever before about the dangers of salt in food. Market research has shown that parents more and more read the labels on processed food packaging and demand to know exactly what they are feeding their children. It is the Sodium in salt that leads to health problems, the FSA recommend the salt intake for children ages 1-3 should be no more than 2g per day (that is 0.8g sodium per day). All food manufacturers, not just of children's food, must label the sodium content, preferably expressed per 100g. Metrohm UK can provide a simple analytical technique for sodium at a price all laboratories can afford. The determination of Na with the Na ISE represents a selective, rapid, accurate and favourably priced method (see Metrohm Application Bulletin 83/5). The 6.0501.100 glass membrane ISE is recommended for samples with a difficult matrix such as food samples. The Na ISE is connected to a Metrohm 781 pH/Ion Meter, the determinations are performed by establishing calibration curves or by carrying out standard or sample additions. For the fully automatic standard addition you need only enter the concentration of your standard and the desired number of additions, the rest is taken care of by the pH/Ion Meter. The working principle is simple, in aqueous solutions, cations are removed from the outer hydrated layer of the glass membrane and replaced by Na+ ions from the sample. This creates a potential (that can be measured) at the boundary layer between the sample solution and the membrane that depends on the activity of sodium. It is also necessary to add a Total Ionic Strength Adjustment Buffer (TISAB) which fixes the ionic strength of the sample and buffers the pH values above 9 as measurements must be carried out in alkali conditions. Difficult samples of complex matrices of vegetables, meat and fish have been recently sampled by Metrohm UK. Reproducible results were obtained by sonicating a known weight of sample in 20ml of distilled water in a sonic bath for five minutes before adding TISAB and analyzing. The total analysis time was on average less than seven minutes, a huge time saving when compared with the traditional 'ashing' technique which can take over 24 hours. Metrohm UK can provide a fast, simple and reasonably priced technique for sodium analysis in the food industry. Contact Metrohm UK on tel 01280 824 824 or visit www.metrohm.co.uk More Articles from Food Trade Review Platinum Collection.(PRODUCTS) September 01, 2005 Weight Watchers spices up its cookie range.(PRODUCTS) September 01, 2005 Snowbird logs on with new sandwich idea.(PRODUCTS) September 01, 2005 New Probiotics yoghurt.(PRODUCTS) September 01, 2005 Healthier options mean healthy profits.(PRODUCTS) September 01, 2005 Find companies classified under Chemical and fertilizer mining not elsewhere classified Find companies classified under Chemical preparations not elsewhere classified

Elimination process of fluorinated anionic surfactants

Abstract:

An elimination process of fluorinated anionic sufactants from exhausted gaseous streams, wherein the gaseous stream is put into contact with aqueous solutions having in the range from 3.5 to 13.8, the aqueous solution density being lower than 1.05 g/cm³, wherein the concentration in the aqueous solution of the fluorinated anionic surfactant removed by the gaseous stream is lower than or equal to 70 ppm.

Representative Image:

Inventors:

Ferrero, Stefano (Alessandria, IT)
Deregibus, Evasio (Alessandria, IT)
Plaque It!



Article

Tin cans - a possible source of contamination of canned food

Food preservation Canning food is a good method of preservation which uses no chemical preservatives and is therefore widely used. Usually cans consist of tin plate which is tin coated steel. Tin is necessary to prevent iron from being corroded by the canned food. Unfortunately tin itself can slowly transfer into the food. The amount of tin taken up by the canned food is affected by many factors. Tin may cause stomach upsets and irritates the digestive tract of sensitive people when present in high concentrations. Fortunately there are no long-term effects due to normal intakes from tin in the food even if it is present in higher levels. An organic compound can be used to line the cans. These fully lacquered cans strongly reduce the levels of tin as long as this protective layer remains undamaged. Nevertheless a new problem arises due to the bisphenol-A which is contained in the lacquer paint and has a potential to interact (endocrine disrupter) with our hormone system.

Voltammetric analysis of tin Differential pulse anodic stripping voltammetry (DPASV) in combination with a hanging mercury drop electrode (HMDE) is an analysis method for determining the concentration of tin in canned food. Prior to the analysis the canned food has to be digested by means of a mixture of concentrated mineral acids. Lead, which was used with tin until lately as a solder (also for cans), can also be determined with the described method from Metrohm. There are a variety of methods described which allow a successful determination of lead even in presence of other metal ions as thallium or cadmium. A specification between Sn(II) and Sn(IV) is also possible. The anodic stripping voltammetry can be carried out on a MVA-2 system. The heart of this system is a 797 VA Computrace enriched with the unbeatable Dosino technique for liquid handling. For your convenience, the methods for the tin and lead determination are already implemented in Metrohm's 797 VA Computrace. Just press the button and start measuring.

Product information MVA-2 system intended for partly automated routine analysis and consisting of the 797 VA Computrace and two 800 Dosinos. MVA-2 Options MVA-3 system for fully automated analysis of small series of samples consisting of the 797 VA Computrace, a 813 Compact Autosampler, two 800 Dosinos, a 731 Relay Box and two 772 Pump Units MVA-3 Send me product information!

Get more information Order our free Monograph Practical Voltammetry (8.757.500X) in English or German. Find more application details in our Application Bulletin 176 (Info Center) Applications for Voltammetry and Polarography Overview of Metrohm VA Instruments

Tips Automation: Up to 18 samples are easily processed fully automatically by the MVA-3 system. Sample preparation: How digestion is done Validation: For the Validation of Metrohm VA instruments using Standard Operating Procedures see our Application Bulletin 276 (Info Center).

Application of a chemoenzymatic glycosylation method to α-chymotrypsin and Candida rugosa lipase surface modifications

Abstract

A recently developed chemoenzymatic glycosylation procedure has been successfully applied on two hydrolytic enzymes, α-chymotrypsin and Candida rugosa lipase. First, a number of sucrose molecules have been bound to the surface lysine residues and then, lengthening of the glycosidic chains has been carried out by the action of a levansucrase from Bacillus subtilis. For both steps, reaction conditions have been studied in order to obtain a range of glycosylation degrees. The influence of glycoside binding on biocatalyst surface characteristics has been assessed and a progressive increase in global enzyme hydrophilic character with glycosylation has been observed. Besides, the study of hydrolytic activity and kinetic constants showed that the performed modifications brought about a certain decrease in enzyme hydrolytic activity and very slight variations in enzyme-substrate affinity.

Author Keywords: α-Chymotrypsin; Lipase; Glycosylation; Hydrophilicity; Activity; Kinetic constants

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Lipases for biocatalysis: development of a chromatograp Journal of Pharmaceutical and Biomedical Analysis Lipases for biocatalysis: development of a chromatographic bioreactor Journal of Pharmaceutical and Biomedical Analysis, Volume 32, Issues 4-5, 8 August 2003, Pages 715-724 E. Calleri, C. Temporini, S. Furlanetto, F. Loiodice, G. Fracchiolla, G. Massolini Abstract The development of a new chromatographic reactor based on immobilized Candida rugosa lipase (CRL) is described. The chromatographic system has been used to evaluate the rate differences by which the product enantiomers of esterolytic reactions catalyzed by immobilized CRL are obtained. The method has been applied to a series of racemic 2-aryloxyalkanoic acids and isosteric analogous methyl esters and to some non-steroidal antiinflammatory drugs 2-arylpropanoic acids methyl esters in order to study the structure effects on reaction rate and enantioselectivity. Lipase from C. rugosa has been non-covalently and covalently immobilized on HPLC chromatographic silica supports to develop an immobilized enzyme reactor (IMER). The reactor was connected through a switching valve to an analytical reversed-phase column, which was used for the on-line determination of the hydrolysis rate by peak area integration. The enantiomeric excess of the hydrolytic reaction products was determined off-line on a CSP utilizing immobilized penicillin G acylase (PGA-CSP). Purchase PDF (341 K) Enantioselectivity of lipases: effects of water activit Journal of Molecular Catalysis B: Enzymatic Enantioselectivity of lipases: effects of water activity Journal of Molecular Catalysis B: Enzymatic, Volume 3, Issue 5, 7 August 1997, Pages 221-230 Ernst Wehtje, David Costes, Patrick Adlercreutz Abstract The enantioselectivity (E) of lipases in esterifications of secondary alcohols with decanoic acid was studied in organic media. The enantioselectivity of 2-octanol differed greatly among the lipases used. Candida antarctica lipase was extremely selective (E = 9 000) while Candida rugosa lipase was much less selective (E = 1.7). Other enzymes (Lipozyme and lipases from Pseudomonas and Rhizopus arrhizus) had intermediate selectivities. In all cases the enantioselectivity for an enzyme was unaffected by changes in water activity. Different methods of determining the enantioselectivity was used: reactions using single enantiomers as well as racemic mixtures. The effect of water activity on enantioselectivity and the enanatioselectivity values themselves were similar irrespective of the method used. The enantioselectivity of other alcohols were also found to be unaffected by the water activity. The enantioselectivity of Pseudomonas lipase was influenced by the organic solvent. The E decreased with increasing hydrophobicity, from 62 in acetonitrile to 40 in toluene and 33 in hexane. 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The emission maximum wavelengths for both intrinsic tryptophan fluorescence and surface hydrophobicity, determined using the probe 8-anilino-1-naphthalene sulfonate, were blue-shifted upon aggregation of CRL. Dynamic light scattering also showed an increase in the molecular weight of CRL as a function of increasing protein concentration. Apparent dissociation constants derived from the three techniques were 0.48, 3.5 and 1.9 μg/ml, respectively. The specific activity of aggregated species (3135 U/mg) was higher than the monomer’s (860 U/mg). The aggregation state of lipases may influence kinetic properties, specificity and interfacial behavior. 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Process for the production of free-flowing rubber powders with silicic acid as filler

Abstract:

A process for the production of free-flowing rubber powders with silicic acid as filler comprises combining a rubber latex with silicic acid filler while stirring in the presence of specific auxiliary agents, adjusting the pH range of the mixture to cause coagulation, and separating and drying the resultant solids wherein the specific auxiliary agents comprise organic surfactants together with colloidal silicic acid.

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Electrochemical Oxidation of Prednisolone at Glassy Carbon Electrode and Its Quantitative Determination in Human Serum and Tablets by Osteryoung Squar

Electrochemical Oxidation of Prednisolone at Glassy Carbon Electrode and Its Quantitative Determination in Human Serum and Tablets by Osteryoung Square Wave Voltammetry

Abstract:
A simple, rapid, selective and sensitive electrochemical method for the direct determination of prednisolone in spiked human serum and tablets was developed. The electrochemical oxidation and determination of prednisolone has been carried out at glasy carbon electrode (GCE) in various aquaeous solution in the pH range of 0.56-12.30 by cyclic (CV) and Osteryoung square wave voltammetry (OSWV). The best results were obtained for the determination of prednisolone by OSWV method in 0.5 mol L-1 sulphuric acid at about pH 0.56. The peak current and peak potential depends on pH, so its influence and also scan rate were studied. The diffusion controlled by nature of the peak was established. This electroanalytical procedure enabled to determine prednisolone in the concentration range 1.0 x10-6-2.0x10-5 mol L-1. This limit of detection (LOD) and limit of quantification (LOQ) were obtained as 3.4x10-7 and 4.5x10-7 mol L-1 respectively. Precision and accuracy of the developed method were checked by recovery studies in spiked tablets and human serum.
Keywords: Prednisolone, Voltammetry, Determination, Tablet and Serum.

Antimicrobial cationic peptides

A novel class of cationic peptides having antimicrobial activity is disclosed. These peptides can be encompassed by the formulas: PRETEXTREPLACED wherein: m is 1 to 5; n is 1 or 2; o is 2 to 5; r is 0 to 8; u is 0 or 1; X.sub.1 is Isoleucine, Leucine, Valine, Phenylalanine, Tyrosine, Tryptophan or Methionine; X.sub.2 represents Tryptophan or Phenylalanine X.sub.3 represents Arginine or Lysine; X.sub.4 represents Tryptophan or Lysine; and X.sub.5 represents Phenylalanine, Tryptophan, Arginine, Lysine, or Proline. The invention also provides a method of producing a cationic peptide variant having antimicrobial activity.
Antimicrobial Cationic Peptides in the Free Online EncyclopediaRead about Antimicrobial Cationic Peptides in the free online encyclopedia and dictionary. Over 700,000 articles on any topic.thefreedictionary.com
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Abstract
The thermodynamics of complexation of the ligands 2,2'-oxybisethanamine (oden) and 2-(2-aminoethyl)aminoethanol (etolen) with the Ni2+ ion were re-investigated by glass electrode potentiometry and titration calorimetry at 25°C and in 0.5 mol dm-3 KNO3. In the case of the ligand etolen the data were consistent with previously reported complexes, Ni(etolen)2+ and Ni(etolen)22+, and associated stability constants. However, the enthalpies of complexation obtained here differ from those previously reported. Reasons for these discrepancies are discussed. For the ligand oden the data could only be explained by the inclusion of the ternary species Ni(oden)OH+ and Ni(oden)2OH+ in addition to the binary species Ni(oden)2+ and Ni(oden)22+. Thermodynamic parameters of complexation for these complexes are reported and compared with those of the etolen complexes.
Keywords: nickel; polyamines; stability constants; thermochemical parameters
view references (41)

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Abstract
Based on a novel ionophore, an ion-selective electrode has been developed for the determination of Cu2+ in drinking water. Its selectivity behavior is characterized and its lower detection limit optimized for measurements with different electrolyte backgrounds. The lower detection limit was 2 × 10−9 M Cu2+ for samples with low ionic background and 1 × 10−7 M Cu2+ with ionic background typically found in drinking water.
Keywords: Potentiometric sensor; ICP-MS; Copper determination; Drinking water
Article Outline
1. Introduction
2. Experimental
2.1. Reagents
2.2. Synthesis of N,N,N′N′-tetracyclohexyl-3-thiaglutaric diamide (cf. Fig. 1)
2.3. ISE membranes and electrodes
2.4. EMF measurements
2.5. Selectivity measurements
2.6. ISEs for optimal lower detection limit
2.7. Measurements in drinking water samples
2.8. ICP-MS measurements
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3.2. Optimizing the lower detection limit
3.3. Measurements in drinking water
4. Conclusions
Acknowledgements
References

Adsorptive stripping voltammetry of Ni(II) using fast linear sweeps

Summary Nickel was determined as bis-(dimethylglyoximato)-nickel(II) by fast cathodic linear sweep voltammetry with a rate of 10 V s–1 after adsorption on a static mercury electrode. The peak width at half-height was 60 mV. For determinations down to 1 ppb of Ni(II), only 40 s accumulation time were required without accelerating measures like stirring or potential application. Resolution and sensitivity were thus similar to differential pulse voltammetry but the duration of a measuring cycle was only 45 s (40 s accumulation, 80 ms for sweep and 5 s for readout). The method was tested with 2 industrial waste water samples and urine. The direct determination of Ni(II) in urine failed, whereas it was possible in the waste water. Concurrent adsorption was the main interference.

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A simple soil test for detecting sites that are nonresponsive to nitrogen fertilization

Introduction
In Illinois, N fertilizer recommendations for corn production are estimated on the basis of a realistic yield goal, which is multiplied by 1.2 to calculate the pounds of N required per acre, less any adjustment for N derived from other sources, such as manure or legumes. A yield-based recommendation may have merit on a long-term basis, but under- or overfertilization is apt to occur in any given growing season since soil N availability is not taken into account. Insufficient application of N can have serious economic consequences for the farmer, whereas excessive fertilization increases the risk of environmental pollution.

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Metal & Metalloid Particulates In Workplace Atmospheres (Atomic Absorption)

Metal & Metalloid Particulates In Workplace Atmospheres (Atomic Absorption)
[160 KB PDF, 25 pages]

1. Introduction

This method can determine the amount of specific metal and metalloid particulates in the workplace atmosphere. The airborne particulates are collected on filters using calibrated sampling pumps. These samples are then analyzed using flame atomic absorption or emission spectrometry. This method can also determine specific metals and metalloids contained in wipe and bulk samples. The identification and quantification of the particulate is directly determined as the element. The elements are:

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Performance and frequency of use of NAA and other techniques during the certification of two new Polish CMRs prepared by INCT

Abstract
Two new candidate reference materials of biological origin, viz. Tea Leaves (INCT-TL-1) and Mixed Polish Herbs (INCT-MPH-2), were prepared, and world-wide interlaboratory comparison involving over 100 laboratories was organised with the aim to certify these materials for the content of possibly great number of trace elements. In this paper a preliminary analysis of the contribution of various analytical techniques to the certification of the new reference materials is presented and discussed with the emphasis on the role played by neutron activation analysis (NAA). The potential significance of “very accurate methods” by radiochemical NAA in the certification process is pointed out. An attempt is made to compare the outcome of the present intercomparison with those formerly organised by INCT as well as with some earlier IAEA intercomparisons in order to demonstrate similarities, differences and trends in the use of the various analytical techniques in trace analysis as a function of time.

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T H E P E R I O D I C T A B L E with SEAWATER ADDITIONS SEA WATER REFERENCES BY ATOMIC NUMBER

Sea Water REFERENCES and DISCUSSION
in Quinby-Hunt and Wilde (1987) and Quinby-Hunt and Turekian (1983) SEA WATER REFERENCES BY ATOMIC NUMBER
Classic Early References

Dittmar, W. 1884. Report on the scientific results of the exploring voyage of the H.M.S. Challenger. H. M. Stationery Office, London, 1.

Forchhammer, G. 1865. On the composition of sea-water in the different parts of the ocean. Roy. Soc. London, Phil. Trans. 155: 203-262.

General References

Quinby-Hunt, M.S. and K.K. Turekian. 1983. Distribution of elements in sea water. EOS, 64: 130-131.

Brewer, P. G., 1975, Minor Elements in Sea Water (Chap. 7) in Riley, J. P. and Skirrow, G. (eds.) Chemical Oceanography, 2nd Ed, Academic Press, London, New York, San Francisco, v. 1, p. 415-496.

Quinby-Hunt, M.S. and P. Wilde. 1986/87. Modeling of dissolved elements in sea water. Ocean Science and Engineering, v, 11, no. 3,4, p. 153-251.

Nozaki, Y. 1997, A fresh look at element distribution in the North Pacific: EOS, v. 78, p. 221-223.

Redfield, A.C., B.H. Ketchum, and F.A. Richards. 1963. The influence of organisms on the composition of sea water. In: Hill, M.N. (ed.) The Sea, Wiley-Interscience, New York. pp. 2677.